When the linear rigidity ratio is small, simplified twin-cantilever free beam(continuous beam) graphic formula shall be adopted whereas the fulcrum section shall be properly reinforced;

The automotive suspension system based on magnetic-rheology absorber has obvious lag non-linear, the non-linear damp and non-linear rigidity etc in the system have great effect on dynamics.

Using the interpolation models for both singular crack tip elements and other crack linear elements, the boundary element formulas of the torsion rigidity and stress intensity factors were given.